Intramuscular 30 percent polymethylmethacrylate (PMMA) implants in a non-protein vehicle: an experimental study in rats / Implante intramuscular de polimetilmetacrilato (PMMA) 30 por cento, associado a veículo não-proteico: estudo experimental em ratos

INTRODUCTION: In the present study, the stability and biocompatibility of a 30 percent polymethylmethacrylate (PMMA) filling material implanted in the masseter muscle of rats were investigated according to the cytologic characteristics presented in the graft versus host reaction. METHODS: The study included 20 rats, which were divided into 4 groups: groups I, II, III, and IV corresponded to animals evaluated 7, 14, 45, and 60 days after surgery, respectively. The implant was placed in the right masseter muscle at the level of the mandibular angle. RESULTS: After 7 days, lymphoplasmacytic inflammatory infiltrates, a fibrous capsule, a large number of neutrophils, macrophages, and exudate were observed. The second group (14 days) showed granulation tissue composed of a lymphoplasmacytic inflammatory infiltrate, newly formed vessels, and a fibrous capsule. However, the second group also exhibited regeneration of the muscle fibers, and a decreased number of neutrophils and exudate. After 45 and 60 days, the inflammatory infiltrate decreased in intensity compared to the first 2 groups. CONCLUSIONS: The inflammatory reaction caused by PMMA is transient and does not compromise the function and the shape of the masseter muscle tissue, suggesting that PMMA is biocompatible.

INTRODUÇÃO: Este trabalho busca avaliar, em ratos, a estabilidade e a biocompatibilidade de um material de preenchimento à base de polimetilmetacrilato (PMMA) a 30 por cento implantado no músculo masseter, por meio do padrão, e a organização reacional no tecido receptor. MÉTODO: Foram utilizados 20 ratos, divididos em quatro grupos: grupo I, que correspondeu ao período de 7 dias de pós-operatório; grupo II, de 14 dias; grupo III, de 45 dias; e grupo IV, de 60 dias. O implante foi realizado no músculo masseter direito, na região do ângulo da mandíbula. RESULTADOS: No período de 7 dias, observou-se presença de infiltrado inflamatório linfoplasmocitário, com formação de cápsula fibrosa e presença de grande número de neutrófilos, macrófagos e formação de exsudatos. Em 14 dias, observou-se a formação de um tecido de granulação composto por infiltrado inflamatório linfoplasmocitário, vasos de neoformação e cápsula fibrosa. Porém, nesse tempo experimental, nota-se a regeneração das fibras musculares e a diminuição do número de neutrófilos e exsudatos. Após 45 dias e 60 dias, observou-se, no tecido muscular, diminuição da intensidade do infiltrado inflamatório, comparativamente aos tempos experimentais anteriores. CONCLUSÕES: A reação inflamatória provocada pelo PMMA é transitória e não compromete as funções e o contorno desse tecido muscular, o que sugere que o PMMA é biocompatível.

Rhinoplasty using Nácul's suspensor system: a preliminary report.

A minimally invasive procedure based on a "suspensory system" is presented for the aesthetic correction of the flat nose. A Goretex monofilament is inserted between the connective tissue and the perichondrium from the septal, upper lateral, and alar cartilages in a quadrangular fashion. When tightened, it shortens the nose and elevates the tip. The procedure is performed on an outpatient basis with the patient under local anesthesia. It offers the patient immediate evaluation of the result. No edema or bruises have been observed. At this writing, 8 months after an application of this procedure, no extrusions or collateral reactions have been found.

Contour of the lower third of the face using an intramusculary injectable implant.

BACKGROUND: The mandible contour plays a major role in the beauty and youthful look of the face. Few methods are available to create or recover facial contours. The author advocates the use of injectable polymethylmethacrylate microspheres suspended in a solution of sodium hyluronate 2%, D-1 propanodiol 10%, and apyrogenous solution 2.5 ml, applied by means of a minimally invasive procedure into deep anatomic planes. The biomatertal is injected in the muscle using microcannulas. METHODS: A review of charts from January of 2001 to December of 2003 was undertaken to search the clinical outcomes from this therapy. RESULTS: This technique for contouring the lower third of the face has been used for 487 patients along 1,383 different sites. There were no significant complications. CONCLUSIONS: Excellent results and a high degree of satisfaction were achieved among the patients and the medical staff.